Human stem cell research is one of the most promising areas of current biomedicine. However, a large proportion of scientifically used stem cells are taken from human embryos that are destroyed for this purpose. Embryo in vitro is a unique existence. Its research is covered in particular by the Convention on Human Rights and Biomedicine. Art. 18 (1) of the Convention states that „where the law allows research on embryos in vitro, it shall ensure adequate protection of the embryo.“ This obligation is not further specified. It is appropriate to ask whether the Convention lays down a minimum standard of embryo protection. Protection of the in vitro embryos is also important in the field of genetic engineering, more specifically in the field of human genome editing. This paper will present the author’s research on the protection of the in vitro embryos in research, both in international law and briefly in the law of the Czech Republic.